Jim DombroskieJim Dombroskie

• Born in K-WBorn in K-W• Attended high school at Attended high school at

Eastwood CollegiateEastwood Collegiate• Worked for a couple of Worked for a couple of

years years • Attended Sir Sandford Attended Sir Sandford

FlemingFleming• Hope to graduate from Hope to graduate from

here (someday!)here (someday!)• Work for Crone geophysicsWork for Crone geophysics

What are they?What are they?

• One celled organismOne celled organism• Solitary or colonialSolitary or colonial• SiliceousSiliceous• Planktic and Benthic Planktic and Benthic

formsforms• Over 60 000 speciesOver 60 000 species• Can be found in Can be found in

almost any moist almost any moist place place

• EukaryoticEukaryotic

Grovea pedalis

EnvironmentEnvironment

• Freshwater Freshwater -puddle -puddle -ditch -ditch -tree (moss) -tree (moss) -lagoon, river, etc -lagoon, river, etc

• Marine Marine -benthic and -benthic and planktic areas planktic areas

Diatom MorphologyDiatom Morphology

• Frustule (skeleton)Frustule (skeleton)

-hypotheca-hypotheca

-epitheca-epitheca

-can have varying -can have varying shapesshapes

• PunctaePunctae

• Raphe (groove)Raphe (groove)

• No flagellaNo flagella

ClassificationClassification

• Phylum Phylum BacillariophytaBacillariophyta

• Class Diatomatae Class Diatomatae • Order CentralesOrder Centrales• Order PennalesOrder Pennales

• Although some put Although some put it in the phylum it in the phylum ChrysophytaChrysophyta

Order CentralesOrder Centrales

• Centric Centric

• Dominate marine Dominate marine environmentsenvironments

• Cret. To Rec.Cret. To Rec.

• Radially Radially symmetricalsymmetrical

-although they can -although they can have varying have varying shapesshapes

Order PennalesOrder Pennales

• Pennate (elongate)Pennate (elongate)

• Dominate non-marine Dominate non-marine environmentsenvironments

• Paleocene to RecentPaleocene to Recent

• Bilaterally Bilaterally symmetricalsymmetrical

-features perpendicular -features perpendicular to long axisto long axis

ReproductionReproduction

• Asexual Asexual

• MitosisMitosis

• Alternation Alternation between bothbetween both

• Progressive Progressive decrease in decrease in sizesize

ReproductionReproduction

• SexualSexual

• MeiosisMeiosis

• Gametes Gametes released and released and combined with combined with anotheranother

• ZygoteZygote

ImportanceImportance

• Responsible for 20%-25%of all carbon Responsible for 20%-25%of all carbon fixation (CO2 + H2O = sugars)fixation (CO2 + H2O = sugars)

• Contribute to atmospheric oxygenContribute to atmospheric oxygen• Major component of plankton (source of Major component of plankton (source of

food for many organismsfood for many organisms• Age dating (many have short time Age dating (many have short time

ranges)ranges)• Dynamite, abrasive, filter, etc.Dynamite, abrasive, filter, etc.• Grass of the SeaGrass of the Sea

HazardousHazardous

• genus genus PseudonitzschiaPseudonitzschia • Domoic acidDomoic acid• binds to the glutamate binds to the glutamate

receptors in the brain receptors in the brain where it causes nerve where it causes nerve cells to transmit cells to transmit impulses continuously impulses continuously until the cells dieuntil the cells die

• eutrophication eutrophication processes occurring processes occurring along our coasts some along our coasts some algae (diatoms!) algae (diatoms!) blooms have caused blooms have caused mass pollution and mass pollution and starvation. starvation.

ReferencesReferences

• http://hjs.geol.uib.no/diatoms/Marbles/index.html-http://hjs.geol.uib.no/diatoms/Marbles/index.html-ssissi

•• http://www.microscopy.fsu.edu/primer/http://www.microscopy.fsu.edu/primer/

techniques/hoffmangallery/diatom.htmltechniques/hoffmangallery/diatom.html• http://hjs.geol.uib.no/diatoms/http://hjs.geol.uib.no/diatoms/• http://www.visualsunlimited.com/browse/vu315/http://www.visualsunlimited.com/browse/vu315/

vu315607.htmlvu315607.html• http://earth.leeds.ac.uk/electronoptics/set3/http://earth.leeds.ac.uk/electronoptics/set3/

diatom_c.htmdiatom_c.htm• http://www.ucmp.berkeley.edu/chromista/http://www.ucmp.berkeley.edu/chromista/

diatoms/diatommm.htmldiatoms/diatommm.html